JP2019020237A - Resolver - Google Patents

Abstract

To provide a resolver capable of accurately detecting the displacement of a shaft-shaped member having two degree of freedom in a linear movement direction and rotation direction.SOLUTION: A resolver according to the present invention includes: a plurality of first protrusions 220 disposed on the circumferential surface of the inner support member on the same circumference; a rotor having an excitation coil 240 and a first flange 230; a plurality of second protrusion parts 321 disposed on the inner peripheral surface of the external support member; a third protrusion part 322 alternately disposed with the second protrusion part 321; a detection coil 341; a detection coil 342; and a second flange 330 disposed with these elements respectively so as to surround the rotor. The plurality of second protrusion parts 321 and third protrusion part 322 are alternately disposed also in a predetermined spiral direction of the inner peripheral surface of the external support member. The second flange 330 is the same in length of the side facing the mutually adjacent second flange 330, and detects the displacement in the spiral direction of a shaft-shaped member.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a resolver, and more particularly to a resolver capable of detecting a position with two degrees of freedom.

  In recent years, with the development of industrial robots, the work content of robots is required to diversify more and more. Along with this, development in the field of robot development has been progressing to easily realize more free movement than ever before. For example, a technique for realizing an operation with one axis and two degrees of freedom with one motor has been proposed. The movement of one axis and two degrees of freedom means that the axis can freely move in the linear movement direction of the shaft and the rotation direction of the shaft. In addition, development for simultaneously detecting such a displacement of the shaft by one sensor has been performed.

  For example, in a non-patent document to be described later, by using a resolver that detects displacement in the rotational direction in a stacked manner in the linear motion direction of the shaft, the displacement of the shaft operating in the spiral direction is detected, and the displacement in the linear motion direction of the shaft is detected. And a technique for calculating by decomposing into a displacement in the rotational direction of the shaft.

"Design and analysis of a resolver for 2DOF tubular motor" Hiroki Tsujimoto, Shodai Tanaka, Tomoyuki Shimono, Takahiro Mizoguchi, Masashi Watanabe, Katsumi Ishikawa, IEEE October 2016

  The resolver described in the non-patent document has succeeded in detecting the displacement of the shaft in the spiral direction. However, the correlation between the output signal and the actual displacement of the shaft is low, and the displacement of the shaft cannot be detected with high accuracy. Therefore, a technique for detecting the displacement of the shaft with higher accuracy is desired.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a resolver that accurately detects the displacement of a shaft-like member having two degrees of freedom in the linear motion direction and the rotational direction. is there.

A resolver according to the present invention includes a cylindrical inner support member fixed to a shaft member, and a plurality of first protrusions arranged on the same circumference from the outer peripheral surface of the inner support member toward the outer side in the radial direction. A rotor having an exciting coil wound around each of the first protrusions and electrically connected to each other, and a first flange provided at a tip of each of the first protrusions;
A hollow cylindrical outer support member, a plurality of second protrusions arranged in the radial direction from the same circumference of the inner peripheral surface of the outer support member, and the second protrusions alternately A third protrusion disposed, a first detection coil wound around each of the second protrusions and electrically connected to each other, and wound around each of the third protrusions And a second detection coil electrically connected to each other, and a second flange provided at the tip of each of the second protrusion and the third protrusion so as to surround the rotor. And comprising
A plurality of the second protrusions and the third protrusions are alternately arranged in a predetermined spiral direction on the inner peripheral surface of the outer support member, and the second flanges are adjacent to each other. The lengths of opposing sides of the second flange are the same, and the displacement of the axial member in the spiral direction is detected.

  With such a configuration, it is possible to detect a voltage linked to the movement in the spiral direction when the shaft-shaped member moves in the preset spiral direction.

  According to the present invention, it is possible to provide a resolver that accurately detects the displacement of a shaft-like member having two degrees of freedom in the linear motion direction and the rotational direction.

1 is a perspective view of a resolver according to a first embodiment. 1 is an exploded view of a resolver according to a first embodiment. 1 is a perspective view of a stator according to a first embodiment. 1 is a perspective view of a rotor according to a first embodiment. FIG. 3 is a front view of a stator and a rotor in the resolver according to the first embodiment. 1 is a basic circuit diagram of a resolver according to a first embodiment. FIG. 3 is a shape and a layout diagram of shoes in the stator unit set according to the first exemplary embodiment; It is a figure for demonstrating the shape of the shoe concerning Embodiment 1. FIG. FIG. 4 is an overall configuration diagram of a resolver according to a second embodiment. FIG. 6 is a layout diagram of teeth in a stator assembly according to the second embodiment. It is a basic circuit diagram of a resolver. It is the figure which showed the signal waveform of the resolver. It is the graph which superimposed and displayed the envelope.

<Embodiment 1>
Embodiment 1 of the present invention will be described below with reference to the drawings. First, an outline of a resolver according to the first embodiment will be described with reference to FIG. FIG. 1 is a perspective view of a resolver 100 according to the first embodiment. The resolver 100 can detect the displacement of the shaft 900 in the spiral direction. The shaft 900 is movable in the linear movement direction of the shaft and the rotation direction of the shaft.

  In the following description, the linear movement direction of the shaft is indicated as direction X. Similarly, in the description of the present embodiment, the rotational direction of the shaft is indicated as direction T. The direction X, which is the linear movement direction of the shaft, may be referred to as the axial direction of the shaft. Similarly, the direction T that is the rotational direction of the shaft may be referred to as the tangential direction of the shaft.

  In the following description and drawings, components common to a plurality of drawings are denoted by common reference numerals. For this reason, the description of the components with common reference numerals will be omitted as appropriate.

  The resolver 100 includes a cylindrical stator unit set 300 and a rotor unit set 200 provided inside the stator unit set 300.

  The rotor unit set 200 is disposed so as to reciprocate in the direction X within a preset range. The rotor unit set 200 is disposed so as to be rotatable in the direction T. A hole 250 is provided in the central axis portion of the rotor assembly 200. The shaft 900 is inserted into the hole 250 and is fixed to the hole 250. Therefore, the shaft 900 and the rotor unit set 200 are interlocked.

  The stator part set 300 is arranged so as to surround the rotor part set 200. In addition, the stator unit set 300 can be fixed to a base member (not shown). The support member of the shaft 900 can also be fixed to a base member (not shown). Therefore, the stator part set 300 is directly or indirectly connected to the support part of the shaft 900.

  The rotor unit set 200 can be applied with an excitation signal from an external circuit (not shown). When the excitation signal is applied, the rotor set 200 generates a magnetic field. That is, the rotor unit set 200 generates a magnetic field corresponding to the excitation signal while moving in the direction X or the direction T. The stator unit set 300 detects the magnetic field generated by the rotor unit set 200. Therefore, the resolver 100 has a structure that can detect the relative displacement in the direction X and the relative displacement in the direction T of the shaft 900 fixed to the rotor unit set 200.

  Next, the configuration details of the resolver 100 will be described with reference to FIGS. FIG. 2 is an exploded view of the resolver 100 according to the first embodiment. The resolver 100 includes a stator unit set 300 and a rotor unit set 200.

  The rotor unit set 200 has two rotors 201. The two rotors 201 are arranged coaxially in the direction X. However, the two rotors 201 are arranged so as to be shifted by 22.5 degrees in the direction T.

  Next, details of the rotor 201 will be described with reference to FIG. FIG. 3 is a perspective view of the rotor 201 according to the first embodiment.

  The rotor 201 has a cylindrical inner support member 210 and eight teeth 220. The inner support member 210 has a hole 250 in the central axis portion. The eight teeth 220 are arranged at equal intervals on the same circumference from the outer peripheral surface of the inner support member 210 toward the outer side in the radial direction. That is, the eight teeth 220 are arranged at intervals of 45 degrees.

  The tooth 220 has an exciting coil 240 and a shoe 230. The exciting coil 240 is a conductive wire wound around the core material of the tooth 220 along the radial direction. The exciting coils 240 wound around the eight teeth 220 are electrically connected to each other.

  The shoe 230 is a flange-shaped member provided at the tip of the tooth 220. The shoe 230 has a top surface 231. Arbitrary points on the top surface 231 are equidistant from the rotation axis 251 of the rotor 201. That is, the top surface 231 is configured on a cylindrical surface drawn by connecting points equidistant from the rotation shaft 251.

  The top surface 231 of the shoe 230 has a shape surrounded by the sides 232, 233, 234, and 235. The top surface 231 has a square shape when projected in the radial direction. The top surface 231 that is a square is formed so that one of the two diagonals is parallel to the rotation axis 251. Further, the top surface 231 is formed such that the other one of the two diagonal lines is along the direction T. That is, the sides 232 to 235 of the top surface 231 are formed along a spiral having an angle of 45 degrees with respect to the rotation axis 251.

  The inner support member 210, the core material of the teeth 220, and the shoe 230 are made of a magnetic material. The magnetic material may be, for example, a general steel material mainly composed of iron. The magnetic material may be, for example, a metal material in which iron is a main component and silicon or ferrite is mixed.

  Returning to FIG. 2, details of the stator will be described. The stator assembly 300 has six stators 301. The six stators 301 are arranged coaxially in the direction X. However, the adjacent stators 301 are shifted in the direction T by 11.25 degrees.

  Next, details of the stator 301 will be described with reference to FIG. FIG. 4 is a perspective view of the stator 301 according to the first embodiment.

  The stator 301 has a hollow cylindrical outer support member 310, eight teeth 321, and eight teeth 322. The teeth 321 and the teeth 322 are alternately arranged at equal intervals from the same circumference on the inner circumferential surface of the outer support member 310 toward the inner side in the radial direction. That is, the eight teeth 321 and the eight teeth 322 are alternately arranged at intervals of 22.5 degrees.

  The tooth 321 has a detection coil 341 and a shoe 330. The detection coil 341 is a conducting wire wound around the tooth 321 along the radial direction. The detection coils 341 wound around the eight teeth 321 are electrically connected to each other.

  The tooth 322 has a detection coil 342 and a shoe 330. The detection coil 342 is a conducting wire wound around the tooth 322 along the radial direction. The detection coils 342 wound around the eight teeth 322 are electrically connected to each other.

  Since the detection coils 341 and the detection coils 342 are alternately arranged, the phase difference of the magnetic field generated by the excitation coil 240 included in the rotor unit set 200 can be detected, and the displacement of the rotor unit set 200 can be detected.

  The shoe 330 is a flange-shaped member provided at the tips of the teeth 321 and the teeth 322. The shoe 330 has a top surface 331. Arbitrary points on the top surface 331 are equidistant from the rotation axis 251 of the rotor 201. That is, the top surface 331 is configured so as to surround the rotor 201 on a cylindrical surface drawn by connecting points equidistant from the rotation shaft 251.

  A top surface 331 of the shoe 330 has a shape surrounded by a side 332, a side 333, a side 334, and a side 335. The top surface 331 has a square shape when projected in the radial direction. The top surface 331 that is a square is formed so that one of the two diagonal lines is parallel to the rotation axis 251. Further, the top surface 331 is formed such that the other one of the two diagonals is along the direction T. That is, the sides 332 to 335 of the top surface 331 are formed along a spiral having an angle of 45 degrees with respect to the rotation axis 251.

  The outer support member 310, the core material of the teeth 321 and the teeth 322, and the shoe 330 are formed of a magnetic material. The magnetic material may be, for example, a general steel material mainly composed of iron. The magnetic material may be, for example, a metal material in which iron is a main component and silicon or ferrite is mixed.

  FIG. 5 is a front view of the rotor 201 and the stator 301 in the resolver 100 according to the first embodiment. In order to facilitate understanding, one rotor 201 and one stator 301 are arranged in FIG. As shown in FIG. 5, eight teeth 220 of the rotor 201 are arranged at equal intervals for each angle 410. In the case of the first embodiment, the angle 410 is 45 degrees. Further, 16 teeth 321 and teeth 322 of the stator 301 are arranged at equal intervals for each angle 420. In the case of the first embodiment, the angle 420 is 22.5 degrees.

  As described with reference to FIG. 2, the rotor unit set 200 includes two rotors 201. The two rotors 201 are arranged with a shift of 22.5 degrees. That is, the two rotors 201 are arranged with an angle 420 shifted. This angle 420 is half of the arrangement angle of the teeth 220. The angle 420 is the same as the arrangement angle between the teeth 321 and the teeth 322 of the stator 301.

  As described with reference to FIG. 2, the stator unit set 300 includes six stators 301. The six stators 301 are arranged with a shift of 11.25 degrees. That is, the six stators 301 are arranged with an angle 430 shifted. The angle 430 is half of the arrangement angle between the teeth 321 and the teeth 322.

  Next, the gap between the rotor 201 and the stator 301 will be described. As shown in FIG. 5, the rotor 201 and the stator 301 are arranged coaxially with respect to the rotation shaft 251 of the rotor 201. The top surface 231 of the rotor 201 and the top surface 331 of the stator 301 are arranged so as to face each other with a gap 400 therebetween. The eight top surfaces 231 are configured on a cylindrical surface drawn by connecting points equidistant from the rotation shaft 251. Similarly, the 16 top surfaces 331 are configured on a cylindrical surface drawn by connecting points equidistant from the rotation shaft 251. Therefore, the gap 400 between the top surface 231 and the top surface 331 is configured to be constant. In other words, the shortest distance between an arbitrary point on the main surface of the top surface 231 and the main surface of the top surface 331 facing the main surface of the top surface 231 is constant. The gap 400 is preferably smaller in order for the detection coil to accurately detect the magnetic field generated by the excitation coil. Specifically, for example, the gap 400 is about 0.5 mm.

  The outer shape when the top surface 231 according to the first embodiment is projected in the radial direction and the outer shape when the top surface 331 is projected in the radial direction are configured to coincide with each other. However, for example, the outer shape when the top surface 231 is projected in the radial direction may be smaller than the outer shape when the top surface 331 is projected in the radial direction, and vice versa.

  Next, the basic circuit of the resolver 100 will be described with reference to FIG. FIG. 6 is a basic circuit diagram of the resolver 100.

The resolver 100 includes a rotor unit set 200 and a stator unit set 300. The rotor unit set 200 includes an exciting coil 240. The stator assembly 300 includes a detection coil 341 and a detection coil 342. An excitation signal is applied to the excitation coil 240 from the AC power source 700. The excitation signal is, for example, a steady high-frequency AC voltage. When the excitation signal is applied, a magnetic field is generated in the excitation coil 240. Receiving the influence of the magnetic field generated in the excitation coil 240, according to the principle of electromagnetic induction, the detection coil 341, the voltages V ₁ generated. Similarly, a voltage V ₂ is generated in the detection coil 342.

A detection signal of the detection coil 341 based on the voltage V _1, between the detection signal of the detection coil 342 based on the voltage V _2, there is a phase difference. The resolver 100 can detect the displacement of the shaft 900 by outputting a detection signal including this phase difference.

  Next, the shape and arrangement of the shoes in the resolver 100 will be described in detail with reference to FIG. FIG. 7 is a diagram illustrating the shape and arrangement of shoes in the stator assembly according to the first embodiment. FIG. 7 schematically shows the state of the stator assembly 300 in a plane when the outer side is observed in the radial direction from the rotating shaft 251 of the resolver 100. That is, FIG. 7 shows a part when the cylinder including the top surface 331 of the stator assembly 300 is expanded in a flat shape. The resolver 100 shown in FIG. 7 is referred to as resolver A.

  In FIG. 7, the vertical direction of the drawing indicates the direction X, the upward direction of the drawing is the plus direction of the direction X, and the downward direction of the drawing is the minus direction of the direction X. The left-right direction of the drawing indicates the direction T, the right direction of the drawing is the plus direction of the direction T, and the left direction of the drawing is the minus direction of the direction T.

  The stator part set 300 of the resolver A shown in FIG. 7 has stators A1 to A6. The stators A1 to A6 are arranged from the minus direction of the direction X toward the plus direction. The stator A1 and the stator A2 are arranged with an angle 430 shifted in the plus direction of the direction T. Similarly, the stator A2 and the stator A3 are arranged with an angle 430 shifted in the plus direction of the direction T. In other words, the stators A1 to A6 are disposed along the angle 440 clockwise spiral direction. The angle 440 in the first embodiment is 45 degrees.

  In FIG. 7, the number “1” is written on the shoe 330 that the tooth 321 has. Similarly, in FIG. 7, the number “2” is written on the shoe 330 that the tooth 322 has. On the shoe 330 of the stator A1, the numeral “2” is shown on both the left and right sides of the numeral “1”. Similarly, in the shoe 330 of the stator A1, the numeral “1” is shown on both the left and right sides of the numeral “2”. That is, in the stator A1, the teeth 321 and the teeth 322 are alternately arranged. The arrangement angle between the teeth 321 and the teeth 322 is an angle 420.

  Next to the stator A1, the stator A2 is arranged. The stator A2 is aligned with the stator A1 on the plus side in the direction X and on the same rotation axis in a state shifted by an angle 430 in the plus direction of the direction T from the stator A1. Therefore, the number “1” of the stator A2 is arranged at the upper right of the number “1” of the stator A1. Similarly, the number “2” of the stator A2 is arranged at the upper right of the number “2” of the stator A1. Thereafter, up to the stator A6, the shoes 330 are arranged in the same pattern. Therefore, in FIG. 7, the shoes 330 are arranged so that the same numbers are arranged in the plus direction of the direction T and the plus direction of the direction X. In other words, the shoes 330 are arranged so that numbers are alternately arranged in the minus direction of the direction T and the plus direction of the direction X.

  Next, the relationship with the shoe 230 which the rotor part group 200 has is demonstrated. In FIG. 7, the shoe 230 which the rotor part group 200 has has approached the location shown with the thick line. That is, in the example shown in FIG. 7, the rotor set 200 excites the teeth 321 of the stator A1 and the stator A3. As described above, the shoe 230 of the rotor unit set 200 corresponds to the positions of the teeth 321 and the teeth 322 of the stator unit set 300. Further, all the shoes 230 are simultaneously displaced by the same amount in the direction X or the direction T from the position shown in FIG. Therefore, detection signals can be acquired from the plurality of detection coils 341 and detection coils 342 included in the stator unit set 300.

  The resolver 100 is used when the shoe 230 of the rotor unit set 200 changes the distance from the teeth 321 of the stator unit set 300 or when the shoe 230 of the rotor unit set 200 changes the distance from the teeth 322 of the stator unit set 300. Displacement can be detected. In the case of the example illustrated in FIG. 7, the teeth 321 and the teeth 322 are arranged in a spiral shape along the plus direction of the direction X and the plus direction of the direction T. In other words, the teeth 321 and the teeth 322 are alternately arranged along the 45-degree clockwise spiral direction. Therefore, the resolver A can detect the relative displacement of the rotor unit set 200 with the highest sensitivity when the rotor unit set 200 is displaced in the 45-degree right-handed spiral direction, that is, the H1 direction shown in FIG. Note that the right-handed spiral direction is also referred to as a right-handed screw direction.

  Next, the shape of the shoe 330 will be described in detail with reference to FIG. FIG. 8 is a diagram for explaining the shape of the shoe 330 according to the first embodiment. FIG. 8 is a diagram when the shoe 330 is projected in the radial direction. The top surface 331 of the shoe 330 has a rectangular shape surrounded by the sides 332, 333, 334, and 335. The top surface 331 has the same length of all four sides from the side 332 to the side 335.

  Further, the top surface 331 has a corner 356 between the side 332 and the side 333. Similarly, the top surface 331 has an angle 357 between the sides 333 and 334, an angle 358 between the sides 334 and 335, and an angle 359 between the sides 335 and 332. . In the first embodiment, the inner angles of the corners 356 to 359 are all right angles.

  The top surface 331 is formed so that a diagonal line connecting the corners 357 and 359 is parallel to the direction X. That is, one of the diagonal lines of the top surface 331 is formed so as to be parallel to the rotation shaft 251. Further, the top surface 331 is formed such that the other one of the two diagonals is along the direction T. That is, the sides 332 to 335 of the top surface 331 are formed along a spiral having an angle of 45 degrees with respect to the rotation axis 251.

  Next, a gap between adjacent shoes 330 will be described. As shown in FIG. 8, the shoes 330 are arranged at equal intervals with the adjacent shoes 330. That is, the gaps 350 between the shoes 330 and the adjacent shoes 330 are all equal. At this time, the gap 350 is preferably small. Specifically, for example, the gap 350 is preferably less than 10% of the length of the shoe 330 in the direction X.

  Moreover, the external shape when the top surface 331 according to the first embodiment is projected in the radial direction may be a diamond shape instead of a square shape. In other words, in the example shown in FIG. 8, the inner angle applied to the angle 356 is equal to the inner angle applied to the angle 358, and the inner angle applied to the angle 357 should be equal to the inner angle applied to the angle 359. In that case, the top surface 231 of the shoe 230 included in the rotor 201 may have the same shape as the top surface 331.

  Further, the outer shape when the top surface 331 according to the first embodiment is projected in the radial direction may be other than the quadrangle. For example, the outer shape when the top surface 331 is projected in the radial direction may be a hexagon, and the lengths of opposing sides of the top surfaces 331 adjacent to each other may be the same. Similarly, the external shape when the top surface 331 is projected in the radial direction may be a triangle, and the lengths of opposing sides of the top surfaces 331 adjacent to each other may be the same.

  With the above configuration, the resolver A illustrated in FIG. 7 can detect the displacement of the shaft 900 in the right-handed spiral direction. In addition, when the adjacent stator 301 is arrange | positioned along the left-handed spiral direction of the angle 440, when the rotor part group 200 displaces in 45 degree | times left-handed spiral direction, with the highest sensitivity, the rotor part pair 200 of Relative displacement can be detected.

  With such a configuration, the first embodiment can provide a resolver that accurately detects the displacement of the shaft-shaped member having two degrees of freedom in the linear motion direction and the rotational direction.

<Embodiment 2>
Next, Embodiment 2 will be described with reference to FIGS. The resolver 100 according to the second embodiment is different from the first embodiment in that a resolver for the right-handed spiral direction and a resolver for the left-handed spiral direction are used in combination.

  The overall configuration of the resolver according to the second embodiment will be described with reference to FIG. FIG. 9 is an overall configuration diagram of the resolver 101 according to the second embodiment. The resolver 101 includes a resolver A and a resolver B.

  The resolver A has the same configuration as the resolver 100 according to the first embodiment. The resolver A has a rotor part set 200 and a stator part set 300. Stator unit set 300 includes stators A1 to A6. The resolver A can detect the displacement of the shaft 900 relative to the right-handed spiral direction.

  The resolver B has a rotor part set 200 and a stator part set 300. Stator unit set 300 includes stators B1 to B6. The resolver B is different from the resolver A in the arrangement of the stator. The resolver B can detect the displacement of the shaft 900 relative to the left-handed spiral direction.

  The shaft 900 is fixed to the rotor unit set 200 of the resolver A and the rotor unit set 200 of the resolver B, respectively. Therefore, the shaft 900, the rotor part set 200 of the resolver A, and the rotor part set 200 of the resolver B are interlocked. Accordingly, the displacement of the shaft 900 with respect to the right-handed spiral direction is detected, and the resolver B detects the displacement of the shaft 900 with respect to the left-handed spiral direction. In addition, the resolver A and the resolver B are installed at positions separated so as not to interfere with each other's magnetic field and have an adverse effect.

  The arrangement of the teeth 321 and the teeth 322 of the resolver B will be described with reference to FIG. FIG. 10 is a layout diagram of teeth in the stator assembly according to the second embodiment. The stator unit set 300 of the resolver B shown in FIG. 10 has stators B1 to B6. The stators B1 to B6 are arranged from the minus direction of the direction X toward the plus direction. The stator B <b> 1 and the stator B <b> 2 are arranged with an angle 430 shifted in the minus direction of the direction T. Similarly, the stator B2 and the stator B3 are arranged with an angle 430 shifted in the minus direction of the direction T. In other words, the stators B1 to B6 are arranged along the angle 440 left-handed spiral direction. The angle 440 is 45 degrees.

  The teeth 321 and the teeth 322 included in the resolver B are arranged in a spiral shape along the plus direction of the direction X and the plus direction of the direction T. In other words, the teeth 321 and the teeth 322 are alternately arranged along the 45-degree left-handed spiral direction. Therefore, the resolver B can detect the relative displacement of the rotor unit set 200 with the highest sensitivity when the rotor unit set 200 is displaced in the 45-degree left-handed spiral direction, that is, the H2 direction shown in FIG. Note that the left-handed spiral direction is also referred to as a left-handed screw direction.

  The relationship with the shoe 230 included in the rotor assembly 200 is as described in FIG. That is, in the example shown in FIG. 10, the rotor set 200 excites the teeth 321 of the stator B1 and the stator B3. As described above, the shoe 230 of the rotor unit set 200 corresponds to the positions of the teeth 321 and the teeth 322 of the stator unit set 300. Further, all the shoes 230 are simultaneously displaced by the same amount in the direction X or the direction T from the position shown in FIG. Therefore, detection signals can be acquired from the plurality of detection coils 341 and detection coils 342 included in the stator unit set 300.

  Next, a displacement calculation method in the resolver 101 according to the second embodiment will be described with reference to FIGS. First, the basic circuit of the resolver 101 will be briefly described with reference to FIG. FIG. 11 is a basic circuit diagram of the resolver 101.

The resolver 101 includes a resolver A, a resolver B, and a displacement calculation unit 600. The resolver A has a rotor part set 200 and a stator part set 300. The rotor unit set 200 includes an exciting coil 240. The stator assembly 300 includes a detection coil 341 and a detection coil 342. An excitation signal is applied to the excitation coil 240 from the AC power source 700. The excitation signal is, for example, a steady high-frequency AC voltage. When the excitation signal is applied, a magnetic field is generated in the excitation coil 240. Under the influence of the magnetic field generated in the excitation coil 240, the voltage V _A1 is generated in the detection coil 341 due to the principle of electromagnetic induction. Similarly, a voltage V _A2 is generated in the detection coil 342. Similarly to the resolver A, the resolver B generates a voltage V _B1 in the detection coil 341. A voltage V _B2 is generated in the detection coil 342 of the resolver B.

  The detection signal from the resolver A and the detection signal from the resolver B are output to the displacement calculation unit 600, respectively. The displacement calculation unit 600 receives the detection coil 341 of the resolver A, the detection coil 342 of the resolver A, the detection coil 341 of the resolver B, and the detection coil 342 of the resolver B, respectively. And the displacement calculation part 600 calculates the displacement of the axis | shaft 900 from the input signal.

  The function of the displacement calculation unit 600 will be described with reference to FIGS. FIG. 12 is a diagram showing a signal waveform of the resolver. FIG. 12A shows an example of an excitation signal applied to the excitation coil 240. FIG. 12B is an example of a detection signal output from the detection coil 341. FIG. 12C is an example of a detection signal output from the detection coil 342. In each figure, the vertical axis represents voltage, and the horizontal axis represents time. For example, a predetermined AC voltage signal 11 as shown in FIG. 12A is applied to the exciting coil 240. When the shaft 900 is in steady rotation, the detection coil 341 outputs a detection signal 21 as shown in FIG. Similarly, the detection coil 342 outputs a detection signal 31 as shown in FIG. Since the detection coil 341 and the detection coil 342 are arranged at different places, the phases of the waveforms of the induced voltages output from the respective detection coils are different. The envelope 22 of the detection signal 21 and the envelope 32 of the detection signal 31 can be calculated from the detection signal 21 and the detection signal 31 by using a technique called synchronous detection.

  FIG. 13 is a graph in which the envelope 22 and the envelope 32 are superimposed and displayed. In FIG. 13, the vertical axis represents voltage, and the horizontal axis represents time. The envelope 22 depicts a sine wave with an amplitude of Vm. The envelope 32 depicts a cosine wave with an amplitude of Vm. That is, the envelope 22 output from the detection coil 341 and the envelope 32 output from the detection coil 342 are out of phase by a quarter wavelength. More specifically, at time t1, the voltage of the envelope 22 is Vm, and the voltage of the envelope 32 is 0. At time t2 advanced by a quarter wavelength, the voltage of the envelope 22 is 0 and the voltage of the envelope 32 is -Vm. In this example, the detection signal of the detection coil 341 indicates that the phase is a quarter wavelength earlier than the detection signal of the detection coil 342. Thus, by calculating the phase difference of the detection signals obtained from the detection coils having different positions in the stator unit set 300, the displacement of the shaft 900 engaged with the resolver 101 can be detected.

式（１）において、ｘは直動方向である方向Ｘにおけるロータ部組２００の変位である。ｌ_ｐは、直動方向である方向Ｘにおける１周期の距離である。また、θは、方向Ｔにおける軸９００の回転角度である。 Next, the method by which the displacement calculation unit 600 calculates the displacement will be specifically described. The resolver A included in the resolver 101 detects the displacement of the shaft 900 with respect to the right-handed spiral direction. The resolver A outputs the electrical angle θ _{e1 according} to the following equation (1). The electrical angle is an angle that makes one cycle of the detection signal shown in FIG. 13 360 degrees.

In Expression (1), x is the displacement of the rotor set 200 in the direction X that is the linear motion direction. l _p is a distance of one period in the direction X which is the linear motion direction. Θ is a rotation angle of the shaft 900 in the direction T.

The resolver B included in the resolver 101 detects the displacement of the shaft 900 with respect to the left-handed spiral direction. The resolver B outputs the electrical angle θ _{e2 according} to the following equation (2).

From the above equations (1) and (2), the displacement x in the direction X of the shaft 900 and the rotation angle θ in the direction T of the shaft 900 can be calculated. Specifically, the displacement x in the direction X of the shaft 900 can be calculated by the following equation (3).

Further, the displacement θ in the direction T of the shaft 900 can be calculated by the following equation (4).

  As described above, the resolver 101 according to the second embodiment includes the resolver A that detects the displacement in the right-handed spiral direction and the resolver B that detects the displacement in the left-handed spiral direction. Any displacement in the rotation direction of the shaft 900 can be detected. Further, the shape and arrangement of the shoes 330 included in the resolver A and the resolver B are the same as those of the resolver 100 according to the first embodiment. Therefore, it is possible to provide a resolver that accurately detects the displacement of the shaft-shaped member having two degrees of freedom in the linear motion direction and the rotational direction.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

100, 101 Resolver 200 Rotor unit set 201 Rotor 210 Inner support members 220, 321, 322 Teeth 230, 330 Shoe 231, 331 Top surface 240 Excitation coil 250 Hole 251 Rotating shaft 300 Stator unit 301 Stator 310 Outer support members 341, 342 Detection coil 600 Displacement calculation unit 700 AC power supply 900 Axis

Claims (8)

A cylindrical inner support member fixed to the shaft member, a plurality of first protrusions arranged on the same circumference from the outer peripheral surface of the inner support member toward the outer side in the radial direction, and the first protrusions A rotor having an exciting coil wound around each of the first coil and electrically connected to each other, and a first flange provided at a tip of the first protrusion,
A hollow cylindrical outer support member, a plurality of second protrusions arranged in the radial direction from the same circumference of the inner peripheral surface of the outer support member, and the second protrusions alternately A third protrusion disposed, a first detection coil wound around each of the second protrusions and electrically connected to each other, and wound around each of the third protrusions A second detection coil that is electrically connected to each other, and a second flange that is provided at each end of the second protrusion and the third protrusion so as to surround the rotor. A stator,
A plurality of the second protrusions and the third protrusions are alternately arranged in a predetermined spiral direction on the inner peripheral surface of the outer support member, and the second flanges are adjacent to each other. A resolver that has the same length of opposing sides of the second flange and detects displacement in the spiral direction of the shaft-shaped member. In the second flange, the gaps between the second flanges adjacent to each other are uniform.
The resolver according to claim 1. The second flange is arranged so that the outer shape when projected in the radial direction is a rhombus and the diagonal line coincides with each of the linear motion direction and the circumferential direction.
The resolver according to claim 1 or 2. The second flange has a rhombus with a right angle inside.
The resolver according to claim 3. The shortest distance between an arbitrary point on the main surface of the first flange and the main surface of the second flange facing the main surface of the first flange is constant.
The resolver as described in any one of Claims 1-4. The external shape when the first flange is projected in the radial direction and the external shape when the second flange is projected in the radial direction are the same.
The resolver as described in any one of Claims 1-5. A first resolver that detects displacement in a right-handed spiral direction; and a second resolver that detects displacement in a left-handed spiral direction that is symmetrical to the right-handed spiral direction, and a first output from the first resolver; Detecting a displacement in an arbitrary spiral direction based on the second output from the second resolver,
The resolver as described in any one of Claims 1-6. The first output and the second output are electrical angles of respective resolvers, and by calculating the sum and difference of the value of the first output and the value of the second output, the linear motion of the shaft member A displacement calculating unit for calculating the displacement in the direction and the displacement in the rotation direction;
The resolver according to claim 7.

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